Nocturnal blood pressure patterns and cardiovascular outcomes in patients with masked hypertension

Masked hypertension (MHT) is characterized by normal clinic and above normal 24-hour ambulatory blood pressure (BP) levels. We evaluated clinical characteristics and CV outcomes of different nocturnal patterns of MHT. We analyzed data derived from a large cohort of adult individuals, who consecutively underwent home, clinic, and ambulatory BP monitoring at our Hypertension Unit between January 2007 and December 2016. MHT was defined as clinic BP <140/90 mm Hg and 24-hour BP ≥ 130/80 mm Hg, and stratified into three groups according to dipping status: (a) dippers, (b) nondippers, and (c) reverse dippers. From an overall sample of 6695 individuals, we selected 2628 (46.2%) adult untreated individuals, among whom 153 (5.0%) had MHT. In this group, 67 (43.8%) were nondippers, 65 (42.5%) dippers, and 21 (13.7%) reverse dippers. No significant differences were found among groups regarding demographics, clinical characteristics, and prevalence of risk factors, excluding older age in reverse dippers compared to other groups (P < 0.001). Systolic BP levels were significantly higher in reverse dippers than in other groups at both 24-hour (135.6 ± 8.5 vs 130.4 ± 6.0 vs 128.2 ± 6.8 mm Hg, respectively; P < 0.001) and nighttime periods (138.2 ± 9.1 vs 125.0 ± 6.3 vs 114.5 ± 7.7 mm Hg; P < 0.001). Reverse dipping was associated with a significantly higher risk of stroke, even after correction for age, gender, BMI, dyslipidemia, and diabetes (OR 18.660; 95% IC [1.056-33.813]; P = 0.046). MHT with reverse dipping status was associated with higher burden of BP and relatively high risk of stroke compared to both dipping and nondipping profiles, although a limited number of CV outcomes have been recorded during the follow-up.